The present invention is directed to a novel heat moldable composition, the process for making said composition and utilitarian devices made of said composition. The inventive composition comprises a blend of (i) gelling agents, such as thermoplastic polymers, (ii) resiliency components, such as styrene-butadiene copolymers, styrene-isoprene copolymers or other resilient amphorous polymers and (iii) softening agents, such as oils. Depending upon the relative proportions of the three aforementioned ingredients, the texture of the inventive composition can range from soft and gel-like to hard and rubbery. Further, the proportions can be adjusted so as to offer, to varying degrees, shock absorbing and support properties, said support properties being directly related to the compressive strength of the composition.
There is a multitude of products which are designed to conform to individual body parts. Examples of these products include chair seats, shoes and pillows, sporting equipment such as helmets, boots, and protective gear, and products for medical uses such as casts, braces and orthotics.
The purpose of these products is generally to provide the benefits of comfort, support, protection and shock absorption to the user. These products can be generic or, more preferably, can be customized to fit a particular individual's body part. With respect to customizable products, most can be fitted once, are not remoldable, and are usually very expensive.
In an effort to provide a low cost custom fitting athletic shoe, Reebok has introduced the Pump.TM.. The Pump.TM. offers a customized fit by utilizing air bladders in conjunction with an air pump. The air bladders are deposed at selected locations on the interior of the shoe. The wearer can then activate the pump thereby filling the bladders with pressurized air. This inflation allows the shoe to better conform to the shape of the wearer's foot. However, the drawback of this design is that the air bladders need to be inflated before and/or during each use. Further, this design does not offer significant shock absorption or protection.
Other athletic shoes on the market contain inserts of air or gel at various selected locations on the interior of the shoe so as to provide support and/or shock absorption. However, these inserts do not provide a customized fit. Additionally, in the case of the air inserts, the air tends to move from side to side during use, thereby reducing its motion control and effectiveness. Also, all of these products tend to wear out over time and become less effective.
The Raichle Company of Switzerland has introduced an ethylvinyl acetate remoldable innerboot under the name ThermoFlex.TM.. While ThermoFlex.TM. is an improvement from the products of the past, it possesses a number of drawbacks. ThermoFlex.TM. offers limited shock absorption; it is too soft for heavier or advanced skiers; the temperature at which it must be molded, 120.degree. C., is too hot to be allowed to come into direct contact with the individuals skin whose body temperature is 37.degree. C.; it is not reusable more than five times; it is difficult to fit and therefore must be applied by a professional.
Unlike the above-described products, the composition of the present invention is firm enough to offer support and shock-absorption, while maintaining enough flexibility to allow comfortable use through conformation to the user's body part. Additionally, unlike other molded products, the compositions of the present invention do not compress or degrade over time.
The present invention is especially suitable for use in ski boots and in-line skate boots. In these instances, a custom fit is particularly important but has been very difficult to achieve. In an effort to achieve a custom fit, foams, silicone foams and silicones have been used for more than twenty years with mixed success. They are generally expensive, difficult to use and may generate hazardous fumes. These products must be fitted by a professional sales person and can only be fitted once. Additionally, since these products are not remoldable and can not be reused, if an error is made in the fitting process, the product must be discarded and the process restarted. Also, most of the currently available products eventually break down and soften after a few months of use.
All documents which are cited in this disclosure are hereby incorporated by reference.